Light pollution is bad for occupational and public health, safety and environment, and sometimes for security, said the International Dark Skies Association.
Studies have found no conclusive correlation between general outdoor lighting and crime incidents. Most property crime is committed during the day, or in well lit buildings.
Outside illumination could draw attention to buildings, goods, or facilities, and help criminals to see what they are doing. Lights triggered by motion sensors are more effective in indicating the pres¬ence of intruders.
Effective safety and security lighting illuminates target areas such as entry points and windows, as determined in a risk assessment. Shielded fixtures decrease glare.
Uncomfortable or temporarily blinding light can distract the eye and cast harsh shadows that could lead to trips, slips, disorientation, or concealment of risks or a trespasser.
Shielded fixtures help you control the placement and amount of light, and to reduce energy usage.
Workers, and security cameras, see more in soft lighting than in spotlights, and also see a wider area beyond the lighting. Our eyes can take up to 20 minutes to adjust to dark areas among brightly lit areas.
Shielded foot lamps along paths provide an alternative to harsh general illumination. A smart lighting plan directs the light where you need it, so you don’t have to choose between security and health, safety, environment, and comfortable night shift lighting.
Save energy, health and environmental impacts
Light should not shine or glare more than 90 degrees from the downward vertical. The American Council for an Energy-Efficient Economy (ACEEE) endorses outdoor fixtures that save energy and light pollution.
Downward concentration of light from fully shielded fixtures, typically requires lower wattage lamps. About 30% of the energy used by unshielded bulbs, light up the sky, and this is bad for human sleep, for urban wildlife, for energy resources, and a range of environmental impacts.
Additional energy savers include timers, dimmers, and motion sensors.
Dark-Sky Association raising light pollution awareness
The International Dark-Sky Association (IDA) aims to conserve energy, and preserve the natural night skies worldwide. Light pollution is an increasing problem due to urban sky glow, light trespass, glare, and clutter.
The International Dark-Sky Association suggests some steps to educate your neighbours about the value of effective and economical lighting;
 Make friends, not enemies. Your neighbors probably don’t realise that some of their lights are bothersome to your workers, security workers or security cameras. Always approach people in a friendly, non-threatening way. Suggest alternatives to your own, and to their current fixtures. Ask them to redirect the light, shield it, or add a motion sensor.
 Be informative. There are many reasons to use sky-friendly lighting. Many IDA articles are downloadable and free for use.
 Do your homework on economic, health, safety, environmental and energy issues. It is useful to know the local costs of electricity (cents per KWH), and the lighting control ordinances. This information is available on most city websites, from your regional utility company, and on your utility bill.
 A list of shielded light fixtures is recommended, available on the IDA website in the Fixture Seal of Approval section, or e-mail email@example.com.
Sample letter to an industrial neighbour
“Dear neighbour, Allow me to introduce myself, I am your neighbour at ,,,,,,,, and I would love to talk to you about safe, environmentally friendly, and secure lighting. I have noticed that you have installed outdoor lights on your property, and I applaud your desire to help improve our area.
“At this time your lights sometimes interfere with our ,,,,,safety /security /view /drivers /operators /environment programme /cameras. I’m sure you weren’t aware of this and I wanted to bring it to your attention and ask your opinion of our lighting, that may also need improvement.
“I am not asking you to remove the lights, but perhaps they can be re-directed onto the ground where they will do the most good.
“We could work together to shield our lights so that they are more effective. Shielding a lamp usually requires a lesser wattage bulb, which is a money saver.
“Shielding reduces glare which can be blinding and produces fewer harsh shadows where the bad guys can hide. Sky friendly lighting provides better security. We are also using motion sensors and timers and would like to learn of your energy-saving solutions.
“Thank you so much for your time and consideration. Sincerely, Your neighbour.”
Energy and light pollution guidelines
 Use light only when and where it’s needed.
 Use only as much light as needed.
 Shine lights down, not up.
 Use efficient light sources for outdoor lighting.
Use your power well
Earth Hour, launched by WWF, is observed every year on the last Saturday of March from 8:30pm to 9:30pm local time worldwide.
People and city managers switch off their lights for the hour in a symbolic call to global leaders to make smart decisions about dealing with climate change.
The 2015 Earth Hour campaign calls on South Africans to use the power of individual voices to join the international movement to stem the tide of climate change.
Light pollution resources
American Council for an Energy-Efficient Economy, www.aceee.org
Consumers Guide to Home Energy Savings, http://www.aceee.org/consumerguide/lighting.htm
Facts About Mercury in CFLs, Press Release, October 1, 2007, Released by Focus on Energy and Energy Star, http://www.focusonenergy.com/data/common/dmsFiles/K_MK_MKPR_PR_2048118480.pdf
Sherman, Lawrence W., Denise Gottfredson, Doris MacKenzie, John Eck, Peter Reuter, and Shawn Bushway; Preventing Crime: What Works, What Doesn’t, What’s Promising. 1997; http://www.ncjrs.gov/works/
US Environmental Protection Agency, http://www.epa.gov/epawaste/hazard/wastetypes/universal/lamps/index.htm
Crime Prevention Through Environmental Design, www.cpted.net
FLAP, Fatal Light Awareness Program, www.flap.org
ENERGY STAR, http://www.energystar.gov/index.cfm?c=cfls.pr_cfls_color
What is Light Pollution, www.darksky.org
Effects of Artificial Light at Night on Wildlife, www.darksky.org